The Da Vinci surgical robot was first cleared by the American FDA in 2000, and is designed to enable minimally invasive, complex surgery.

This surgical robotic system is a considerable improvement over conventional laparoscopy, in which the surgeon operates while standing, using hand-held, long-shafted instruments, which have no wrists. With conventional laparoscopy, the surgeon must look up and away from the instruments, to a nearby video monitor in two dimensions (one camera) to see an image of the target anatomy. The surgeon must also rely on their patient-side assistant to position the camera correctly

In contrast, the surgical robot allows the surgeon to operate from a comfortable, seated position at the console, with eyes and hands positioned in line with the instruments. To move the instruments or to reposition the camera, the surgeon simply moves their hands and the instruments and two-lens camera flow as if part of the surgeon. The instrument wrists allow the instruments to bend once in the patient, reducing the need to open new incisions for difficult areas.

The Da Vinci System Overview

However, there has been a problem. It has transpired that surgeons often need more than two hands when it comes to positioning additional instruments such as endoscopes or lasers.

So, to a team from the Hamlyn Centre for Robotic Surgery at Imperial College London, have added a gaze directed assistance unit to the Da Vinci system.

Their device uses the surgeon's gaze to direct tools. It shines an infrared LED on each eye, and cameras track the relative movement of the pupil and the "glint" of reflected light on the cornea to calculate where the surgeon is looking. The information is used to move the instrument to a new position on the patient. Since the surgeon will only want to use the feature at certain times in the procedure, the device is activated by a foot pedal.

The team hopes to present test results at the IROS 2008 conference in Nice, France, later this month. Team member Guang-Zhong Yang claims the gaze-tracker device is accurate to within 3 millimetres, although they are hoping to improve on this. He says it should provide more instant and precise control than a human assistant. "It could be useful in cardiovascular or gastro-intestinal surgery, which require lots of complex manoeuvres," he says.